Current sense resistors are commonly used to sense or measure current flow in an electrical circuit. Current sense resistors sense current by measuring the voltage drop across the resistor where the current is then calculated based on Ohms's Law: V=I*R, where R denotes the resistance of the current sense resistor, V denotes the measured voltage across the sense resistor and I denotes the sensed current value.
Current sense resistors are often used with current monitor integrated circuits to measure current consumption in an electrical circuit, such as at a power supply. Most current monitor integrated circuits use an external current sense resistor to sense the current flow at the electrical node under test. That is, the current sense resistor is a discrete component external to the current monitor integrated circuit. In some cases, the current sense resistor may be integrated into the packaging of the current monitor integrated circuit.